Imaging diagnosis of monostotic fibrous dysplasia in thoracic and lumbar spine vertebrae

The X-ray radiograph, CT scan and MRI appearance of 5 patients with pathologically proven fibrous dysplasia in thoracic and lumbar spine vertebrae were retrospectively analyzed. Plain radiographs, CT scans and MR images showed the presentation of eccentric lesion with intact cortex bone and marginal sclerosis in vertebral bodies without involvement of vertebral appendix and extraosseous soft tissue. The lesion masses were round (one being oval-shaped) and radiolucent in plain radiographs and CT scans. Homogeneous long signal was observed on T1 weighted image and strongly enhanced when gadolinium was administered. On T2 weighted MRI, short signal was found in the anterior part of the mass, long signal in the posterior part, and short and slight long signal in the middle part, without partitioning and laminating change. There was a good correlation between radiological features and surgical findings. These findings may be useful to diagnose fibrous dysplasia in spine.